Design and Simulation of Transparent Electromagnetic Shield Based on Ultra-miniaturized Grid with a Wide Band

An ultra-miniaturized transparent electromagnetic shield based on hollow hexagonal grid with the grid line less than 5 microns is proposed. The proposed structure contains two layers of metallic grid and two layers of transparent substrate. Each unit cell is only about λ₀/68 (λ₀ is the wavelength of the center frequency of shielding band in free space). The surface metal occupancy of the structure is only 6.6%, therefor, a high transparency of more than 90% can be realized theoretically. Simulation results show that shielding effectiveness above 45dB can be achieved throughout the band of 5-30GHz. Additionally, the proposed structure is insensitive to the polarization and the incidence angle of the illumination due to its small unit size. In this paper, multiple parameters have been studied to explore the influence they have on the shielding effectiveness.